CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, shares issued (in shares)	19,382,400	19,254,681
Treasury stock at cost, shares acquired (in shares)	986,761	824,374